Impacts of climate change from the Arctic to Goshawks on Haida Gwaii?

Submitted article-Biologist Frank Doyle recently has given several community presentations showing how a changing climate is not only changing our weather, but also impacting species survival, from here to the Arctic. Using historic weather data available online from the Environment Canada weather page for Sandspit, he showed that since1949 the total monthly rainfall in the months December to June has, on average, been increasing. He explained how such trends in climate patterns are only seen when you look at the long-term patterns, and not any individual years. Based on his work with the Inuit on Herschel Island in northern Yukon, he highlighted some of the dramatic impacts that a changing climate is having on the land and ecology of the area and therefore the traditional use of the land and the oceans. The Herschel Island work, which involves scientists from all over the world, reveals that small changes such as timing of insects hatching, can affect everything up the food chain and ultimately the people who rely on these resources.The weather information for Herschel Island dating back to 1929 shows spring is generally coming earlier. This means a longer growing season, which favours such plants as the grasses and bushy willows, rapidly starting to become established in areas far further north than their typical range. This and many other changes, including the well documented earlier melt of the sea ice, and melting of the permafrost, are resulting in less predictability of hunting times and locations and the abundance of traditional foods.Change has always been part of the tundra ecosystem for the Inuit and First Nations who have lived there for thousands of years, but the change in recent decades has occurred very rapidly. Therefore, the Inuit invited scientists such as Frank Doyle to work with them, and try to give some direction of how the ecosystem is changing, and what it will look like in the years to come. Here on Haida Gwaii, a research and inventory team has been working for over a decade on understanding the habitat requirements of many focal species in the forests including the goshawks. Focal species are those which best reflect the health of an ecosystem. Frank gave an update of that work, and discussed how the observed increased rainfall in spring may further reduce the ability of the islands to continue to support goshawks. A total of 14 goshawk nesting areas have now been found on the Islands. As with goshawks elsewhere, the pairs of birds are regularly spaced (~ 11km apart) in suitable habitat. Based on the forest types they occupy, the islands may support another 10-15 territories. As with many of the islands’ birds and mammals, goshawks here appear to be genetically separated from other coastal populations, which indicates the habitat on the islands once supported a much larger population.Unfortunately, both the introduced mammals (deer, raccoon, squirrels, etc), and past large scale commercial harvest practices have likely reduced the abundance of native goshawk prey. Research shows that goshawks rely on large prey that live in mature-old forests. Unfortunately, the goshawks’ large size means that second growth forests do not provide comparable foraging conditions until they are at least 80 years of age. The presentation showed we have ample information to manage for goshawks in the old growth, and as well as ways to speed up goshawk habitat recovery in second growth through thinning and pruning.Unfortunately, with all this knowledge, goshawks here, like their counterparts on the mainland, may now face a further challenge from a changing climate. Like many birds, goshawks breed less successfully in wet weather. The increasing rainfall may be another stress facing the island goshawk population and other birds, mammals, plants and the people on the islands. Just as in our gardens, the weather in any year will result in some plants doing well while others may wither and die, in the same way any overall changes in climate may be expected to affect the native animals, plants, fish, insects, etc., with some liking the change, while others not. Frank stressed the only ways to determine how these changes are impacting the different species is to ensure that selected focal indicator plants and animals are monitored. Hand in hand with this approach, we need to ensure that focal species are given the habitat conditions to adapt to these changes. He also urged that we take the time to look at the observed and predicted changes in climate on the island, to ensure that our long-term decisions about other sectors such as fisheries, or community projects, are also made in the context of these changes in weather patterns.